Semiconductor image sensors are used in various imaging devices, such as video cameras. An image sensor device includes an array of picture elements (pixels) for detecting incident light and recording an intensity of the incident light. Typically, an image sensor device includes charge-coupled device (CCD) image sensors or complimentary metal-oxide-semiconductor (CMOS) image sensor devices. The CMOS image sensor generally utilizes light-sensitive CMOS circuitry to convert photons into electrons. The light-sensitive CMOS circuitry typically includes a photo-diode formed in a substrate. As the photo-diode is exposed to light, an electrical charge is induced in the photo-diode. Each pixel may generate electrons in response to incident light. The electrons are converted into a voltage signal in the pixel and further transformed into a digital signal. In image sensor industrial, increasing the resolution of the image sensor is continuously an aim.